59 
“Analysis of one of the Trefriw Mineral Waters,” by 
Thomas Carnelley, B.Sc. Communicated by Professor 
H. E. Roscoe, F.RS., &c. 
An analysis of this strongly ferruginous mineral water has 
not, so far as the author has been able to learn, been pub- 
lished before any scientific society ; and though two general 
analyses of it have previously been made, the first by D. 
Waldie, Esq., in 1844, and the second by Dr. Hassall in 1871, 
and published in the form of pamphlets for public reading 
by Dr. Roberts and Dr. Hayward respectively, yet as it is 
peculiar for the extremely large quantity of iron and 
alumina that it contains, and as its composition has varied 
considerably since it was analysed by the last named che- 
mist (whose results also varied from those of the first), it is 
thought that another and more complete analysis will not 
be out of place. 
The village of Trefriw is situated on the left bank of the 
Conway about miles from Llanrwst and between the 
latter place and Conway. The springs, which now belong 
to a company and are often visited by invalids as they are 
said to be good for the cure of diseases of the digestive 
organs and of the skin, are close to the high road which 
runs between Conway and Llanrwst, and are rather over a 
mile from the village. The entrance to them is a short way 
up the side of the mountain called the Alt cae Coch, and 
consists of an underground passage cut in the rock. There 
are at present two springs (formerly there were three), one 
opposite and close to the entrance, the other at the end of a 
gallery 10 or 12 yards long to the right. The former water 
is used to supply the baths, and the latter exclusively for 
drinking ; they differ considerably in the relative propor- 
tions of their mineral constituents, but it is only the last 
named which is the subject of this paper. 
The water, which flows into a basin cut in the rock, is 
said to be uniform in quantity and issues at the rate of 
